Automatic shaft reverser and torque governor machine



J LL

Feb. 9,1954 HJULIAN 2,668,451

AUTOMATIC SHAFT REVERSER AND TORQUE GOVERNOR MACHINE Filed Dec. 5, 1950 5 Sheets-Sheet l llnlflul WWI,

Feb. 9, 1954 Q HJULIAN 2,668,451

AUTOMATIC SHAFT REVERSER AND TORQUE GOVERNOR MACHINE Filed Dec. 5, 1950 5 Sheets-Sheet 2 /liiiil ll llll Alllifll (I' lullllmll J. A. HJULIAN Feb. 9, 1954 AUTOMATIC SHAFT REVERSER AND TORQUE GOVERNOR MACHINE 1 l l I |l Feb. 9, 1954 J, HJULIAN 2,668,451

AUTOMATIC SHAFT REVERSER AND TORQUE GOVERNOR MACHINE Filed D60. 5, 1950 5 Sheets-Sheet 4 Patented Feb. 9, 1954 AUTOMATIC SHAFT REVERSER'AND TORQUE GOVERNOR MACHINE Julius A. Hjulian, Palos Heights, Ill., assignor to Crane 00., Chicago, Ill.

Application December 5, 1950, Serial No. 199,299

13 Claims.

This invention relates to a valve testing machine or the like, and, more particularly, it pertains to an automatic shaft reverser and torque governor machine which is preferably employed in transmitting power from a given power supply source.

Upon reading thefollowing disclosure, it will be apparent that the practical application of this invention is very extensive. However, for purposes of clarity in the understanding of this invention, a specific application of valve testing will be considered herein. The said application is concerned with the-repeated operations of opening and closing a valve. The said operations general may be said to simulate-the "actual serviceconditions to which the said valve may be subjected. h c "Thus, it is an important object of this invention toprovide a machine which is adaptable to effect: the transmission of rotary motion to a valve stem or the like, wherein a predetermined valve closing torque may be applied to said valve stem, and whereupon said stem rotation will be automatically reversed for a predetermined number of revolutions, after which the direction of said stem rotation is again automatically reversed while the power supply operates continuously in but one direction.

It is another object of this invention to provide a machine for transmitting continuous rotary motion and predeterminatelylimiting the torque on the driven shaft and also the number of revolutions in one direction of rotation of the driven shaft while the said machine is adjustable in' these functions.

Another object is to provide a machine which .will transmit rotary motion and automatically reverse without requiring the use of the usual electrical devices, such as relays, reversing switches, solenoids, and the like. instill another object is to provide a maohin which will transmit rotary motion and limit the shaft torque without damaging the machine bythe use of shear keys or the like.

Other objects and advantages will become more readilyapparent upon proceeding with the following description read in light of the accompanying drawings, in which 7 Fig. 1 is a plan view of a preferred embodiment of this invention.

Fig. 2 is a front elevation view of the embodiment shown in Fig.- 1.

@Fig. 3'is an enlarged fragmentary sectional plan'view of an end portion of Fig. 2.

Fig. 4 is an enlarged plan fragmentary sectional view of an intermediate portion of Fig. 2.

Fig. 5 is an enlarged fragmentary sectional plan view of an end portion of Fig. 2.

Fig. 6 is a fragmentary sectional view taken on a line 6-6 of Fig. 1.

Fig. 7 is a fragmentary sectional view taken on a line 1-1 of Fig. 1.

Fig. 8 is a fragmentary sectional view similar to the view shown in Fig. 7, but showing a different position of the device.

Similar reference numerals refer to similar parts throughout the several views.

As shown in Fig. 1, the machine consists essentially of a base plate It) having suitable holes therethrough for bolting to a casing (not shown) or other support means which may enclose the entire mechanism if desired. A conventional power drive means (not shown) is preferably employed and may be geared with a gear or sprocket ll preferably keyed onto a shaft I 2 extending outsidethe said casing. The direction of rotation of the said drive meansis of the usual practice as being in a direction to impart counterclockwise rotation to the sprocket H as seen in Fig. 2, while a shaft is of the machine extends from the said casing to suitably connect to a rotatable valve stem (not shown) and automatically reverses the direction of such stem rotation as desired and as hereinafter described. It should be here noted that the direction of rotation of s rocket H is determined by gearing, to be later described, and rotat on of the valve stem will be assumed to be in accordance with standard practice, i. e., clockwise for closing when lookin down on the valve.

Following through the motion of the said mechanism from the said drive means, a bearing 54 mounted on the base plate l8 supports the driven shaft 2. The latter member has a bevel gear I (i secured to the end thereof in a conventional manner; Two oppositely d s osed bevel gears H and I8 constantly mesh with the bevel gear is and are mounted on the shaft [3 so as to be free to rotate relative thereto.

Mounted over the shaft l3. between the bevel gears I1 and I8, is a cyl ndrical double dog clutch member l9 having inner peripheral longitudinal grooves 2| (see Fig. 4) to receive corresponding splines 22 of the shaft 13 whereupon the dog clutch member I9 is axially moved by means hereinafter described. Driven clutch members '23 and 24, which are relatively nonrotatably mounted within bevel gears l1 and I8, respectively, may be separately engaged by the 2,668,451 T' i" s 3 slidable dog clutch member I9, thus transmitting the drive power to the shaft, is and thereby enabling the latter member to be rotated in either direction according to which one of the driven clutch members 23 and 24 is engaged.

Assuming that the driven clutch member 23 is engaged with the sliding clutch member 19, as is shown in Fig. .1, ;-it will be apparent that the shaft t3 will rotate in .one direction until a predetermined resisting torque is applied thereto. The said resisting torque may be the result of seating a valve closure member, (not shown) which is reciprocated by the valves stem ibe'ing axially connected to the end of the shaft 13. The influence of the said resisting torque on "the shaft l3 causes a sleeve 26 mounted thereon to move axially outward as two diametrically opposite end portions of a shaft roller pin '21 roll downwardly on two respective cam surfaces 28 located on the end of the sleeve 25. Note that reversed rotation .of shaft 13 would provide a more definite drive between pin ,2] and sleeve 2.6, since the pin is more definitely received on the upper side thereof by the sleeve cam surface which is notched. It should .also be noted that a separation or clearance exists in the shaft 13 .at a portion designated .31) within the sleeve 26 and thereby permits relative rotation between the sections of the .shaft 13 when theresisting torque stops rotation of the end section, which is designated 23. Since the driving power is :continucos, the opposite shaft section 31 continues to rotate, thereby causing the roller pins .21 to ride on the .cam surfaces 28. Normal rotation of the shaft 13 is effected through the roller pins ,21, the latter members being inirelatively tight relation to bear against anotched portion of the cams 28 by means hereinafter to be described. Two diametrically .opposite longitudinal slots 32 are provided in. the sleeve .25 to receive a shaft pin .33, thereby allowing for the axial displacement of the-sleeve 2.6 while transmitting rotation.

The outer end of the sleeve .26 abuts an axially movable non-rotatable yoke 34 mounted on the shaft 13 and having ball bearings .31 therein, as shown in Fig. .3. Another non-rotatable yoke 38 is threadedly mounted .on the outer end of the shaft is and is preferably provided with the .ball bearings 41. As shown in Figs. 1 and 3, two springs 522 of predetermined strength are disposed between the two yokes 34 and .38 which are .sup ported upon two crossbar-s 43, the latter members being mounted on the base plate l under the ends of the yokes 34 and Y38. Thus, under the influence of the springs 42, the yoke 34 is held inwardly against the sleeve for the previously described reason of maintaining the sleeve 26 in driving relation with the section 31 of the shaft l3. When the sleeve 25 is moved outwardly as described, the yoke 34 moves outwardly, and also a, rod 44 which is connected to the yoke 34 is axially moved to effect reversal of the shaft 13 by shifting the'sliding clutch member #9 in a manner hereinafter described. It should be understood that the strength .of the sprin s 42,

against which the yoke 34 moves, determines the limit of the allowable resisting torque. The yoke .38 is mounted on the threaded bushing 39 which permits the axially adiustablepositioning of the yoke 35, thereby providing for the desired tension adjustment of the springs vn12. Also, the springs 42 may be easily removed from the yokes 34 and 38 and replaced by springs having a different strength characteristic if there is a need for a further change in the spring resistance.

The previously described end of the shaft l3 may be supported by conventional bearings 46 and 4'! mounted on the base plate It]. Manual means of stopping the rotation of the shaft section 29 may, as best shown in Fig. 6, be provided in the bearing where a spring loaded plunger 45 having an inner lug member 48 is forced downward "to engage in a slot 49 on the shaft section 2-9, thereby preventing rotation of the latter member while the shaft section 3| rotates as the pin 21 merely rolls over the cams 28.

Referringnow to the opposite end of the shaft 113 as shown :in Figs. 1 and 2, suitable conventional'bear'ings 5| and 52 are positioned on the base plate -19 to support this end of the shaft i3 which .has a threaded portion 53. A dial 54, having an internally threaded sleeve nonrotatably connected therewith (see Fig. 5), is mounted to cooperate with the shaft threads 53 and to reciprocate axially thereon. A cylindrical member .51 mounted over 121186168578 .56 .normally maintains thedial-54 in rotati-ve relation with the shaft laiby means .of a spring loadedpin 58 which is mounted on .the cylindrical member 57 .to be received within holes in the outer rim of the :dial 54. The cylindrical member 51 is held in nonrotative position by an arm 68 which extends therefrom, and member 51 is axially moved with the died 54 .byconnecting thereto through ascrew 58 in the member 551 and having an end received within a circumferential groove .61 in .the sleeve .55 (seeEig. 5)- Thus, the dial 54 may be adjust- ;ably positioned .on the shaft 13 by withdrawing the pin 58 from a dialhole and screwing thedial sleeve 56 along the shaft [3. .By the above mentioned adjustment, the exact number of shaft revolutions may be provided before reversal of the shaft 13 takes place. A more detailed :description of the latter feature is hereinafter given. .A scale 52 may .be fixedly positioned to indicate, through a pointer :63 connected to the arm 50, the number of shaft revolutions before reversal thereof.

Continuing .to analyze the operations of the mechanism, as the dog clutch member 49 is engaged with the drivenclutch member 23, the dial assembly, generally designated 55, moves outwardly on the shaft 13 until the resisting torque is applied thereto. Since thesaidresisting torque reverses the direction of shaft rotation by shifting the clutch member 19 to engage with driven clutch member 2-4, the dial assembly 55 moves inwardly on the shaft 13. In a predetermined amount of inward movement, the arm .60 slides over a cylinder 64 until abutting a collar 66 on the inner end of the cylinder 64, as best shown in Fig. 5. The cylinder 64 is threaded on .a rod Bl'which extends through a mounting E8 of Fig. '1 and operates on two springs 89 and 1 I which are within casings and 65a, respectively, are thereby compressed by the inward movement of the dial assembly '55 by virtue of the construction shown in Fig. 4. The amount-of spring compression-may be adjusted by threadedly engaging the cylinder '64 along the rod-61 as apparent in Fig. 5, and a screw :12 shown Fig. 2 is provided to extend through the collar SE-t0 interlock the "two members 64 and 61 together. The springs 68 and H are preferably positionedwithin the telescoping casings 65 and 65a which contain apertures to prevent possible sluggish action of air compression or the .like.

It should here be noted that :a clutch actuator member 13 is supported by the bearings 41 and 51 and slides thereinunder the influence 0f the -springs 89 andv 1| in a manner hereinafterdescribed. End portions 10 and 15 of the actuator member 13 are adjacent the outer ends of springs 59 and 1|, respectively, and thereby position the member 13 by spring action. The central portion of the member 13 contains a guide 14 which contacts the sliding clutch member |9 to transmit the displacement of the member 13 to the sliding clutch member |9 while permitting free rotation of the clutch member l9. Thus, it will be understood that the action of the springs 59 and 1| provides for the positioning of the dog clutch member l9 and which affects the direction of rotation of the shaft I 3.

In the inward limit of movement of the dial assembly 55, a pin 18 projecting from the arm 60 abuts a rod 11 (see Figs. 4 and 5) disposed within a sleeve portion 18 of the member 13, The pin 15 moves the rod 11 axially inward to release a catch 19 (see Fig. 8) which is pivotally mounted on the member 13 and secures the same against the influence of the springs 89 and 1| (see Fig.

-1). An end of the catch 19 is received within a slotted shank 82 of member 13 of Fig. 7 where a pin 83 pivotally secures the catch to the-shank 82. Thus, as shown in Fig. 1, the release of the catch 19 shifts the member 13 and the dog clutch member l9 under the extension of the spring 89, as hereinafter described. The clutch member l9, thus shifted, again engages the driven clutch member 23, and thereby reverses the rotation of the shaft l3.

The rod 11 of Fig. 4 is preferably spring loaded, by means of the spring 88 which is disposed within the sleeve 18, to effect the return thereof to the original position. Also, the catch 19 of Fig. 7 is spring loaded, by the spring 84 on the member 13, and thereby is yieldingly held downward while being supported in the lowest position by the bar 8| projecting from the mounting 68. When the catch 19 is returned to the downward position, the member 13 is thereby prevented from shifting to its previous position by a stop pin 90 projecting through the catch 19 to abut the bar 8|. Thus, the spring 1| is maintained partially compressed by the spring abutting the end 15 of the member 13 when the dial assembly 55 has again moved outward.

The shaft l3 then rotates in the reversed direction which causes the dial assembly 55 to again move outwardly. After the predetermined number of revolutions of the shaft l3, the resisting torque becomes effective causing the rod 44 to move outwardly by the means previously described. An inward portion of the rod 44 is received within a sleeve portion 86 of the member 13, as shown in Fig. 7, and a groove 81 on the inner end of the rod 44 receives a downwardly projecting end 85 of the catch 19 which is secured against the influence of the springs '89 and 1| by means of the stop pin 90 abutting bar 8| Thus, the outward movement of the rod 44 lifts the catch 19 to permit the spring 1| of Fig. 1 to shift the member 13, and to place clutch |9 in engagement with driven clutch member 24.

The rod 44, as shown in Fig. 3, is provided with a spring 88 within a sleeve 98 and allows for relatively slight adjustments in the length of the rod 44. More particularly, the spring 88 'effects an inward displacement of the groove 81- of Figs. 7 and 8 in the end limit of inward movement of the dial assembly 55 of Fig. 1. Thus, the action of the catch 19 is more rapid in relation tothe movement of the outer end of the rod 44.

The sliding clutch member 19 may be locked in a neutral position, by'means of a collar member 89 looking within :jtransverse grooves 9| located on the member 13. The collar member 89 that eight revolutions are desired in the opening or closing of a valve to be tested, the said valve isset in a closed position while the shaft stop plunger 45 of Fig. 1 is held downwardly as the dial assembly moves outwardly by either the engagement of gear H with clutch member |9 or by the previously described positioning of dial 54 on shaft 3. When the scale pointer 63 indicates "8 on the scale 62, the plunger 45 is released, thereby providing for the application of the resistant torque of the seated valve and immediately reversing rotation to permit the said valve to open in the eight revolutions before the shaft |3 reverses for another eight revolutions when the pin 18 will trip catch 19 to again reverse the shaft l3. The above mentioned setting is thus permanently fixed for that particular test.

A summary of the shaft reversing operation is hereinafter given in connection with Figs. 7 and 8. Fig. 7 shows the details of the catch mechanism in a position of the machine as shown in Figs. ,1 through 5. Fig. 8 shows the same section of the catch mechanism as that shown in Fig. '7, after the machine has operated to reverse the shaft.

Thus, in Fig. 7, the catch 19 is held downwardly by spring 84 to lock the catch and the actuating member 13 with the bar 8| through stop pin 90. Since catch 19 is connected to actuator member 13 through the common shank 82, actuator 13 is maintained in a set position with catch 19. In the view shown in Fig. 7, this set position secures member 13 to the left thereby providing the engagement of clutch member l8 with driven clutch member 23, as shown in Fig. 1.

As best shown in Fig. 1, upon predetermined operation with the above described setting, the previously mentioned resistant torque will become effective on shaft end 29 of shaft l3, thereby causing the roller pin 21 to roll down on cam 28, as seen in Fig. 1, as the shaft 3| continues to rotate. As in the previously described manner, the yoke 34 is thus outwardly displaced as is rod 44 which is connected thereto,'and the following described spring loading or cocking and releasing, or trigger action, takes place.

Again referring to Fig. '7, rod 44 is thus displaced to the left, releasing catch 19, as groove 81 is withdrawn fromgthe end 85 of catch 19, the stop pin 98 is caused to lift above bar 8|. Under the previously'arranged and described compression of spring 1| in casing 65a, the

spring then .acts against theactuator' end 15 to shift the then released actuator 13 to the right as shown in Fig. 8. Catch 19' is again held downwardly by-the spring 84 where the stop pin 98 then engages the bar' 8| to secure the catch against displacement to theleftr The above described shiftingof the actuator 13 positioned theclutch? member ibx'tof engage with drivenclutch member '24 xandithefebyi'reverse the rotation of shaft '13, aslapparent 'Fig. 1. The rotation of shaft 13 then actuates the dial mechanism 55 in an inward direction. As previously noted in connection with'Fig. a,

:inward movement of the dial'mechanism 5.5 effects axially inwardmovement oflrod' 6'! which compresses springs F69 and H within the casings 85 and 65a by shouldering on their respective casing end portions.

Continued inward movement of dialmechanism 55, positions pin f6 against ro'd H as shown 8. It should here be apparent thatfurther inward movement of pin I6 will force rod nected to the actuator 13 and the latterZ-is' again displaced by the spring action. This time, the

"catch mechanism is returned to the position .showninFig.'7.

The spring H in casing 85a is thus secured in a compressed position by'the actuator 13 and the actuator end being maintained in position by the catch 19.

The foregoing description of a valve tester device is most suitable for testing the valve packing, stem friction, and the like; If it is desired to test theclosure member and seat for fluid tightness after a number of operations of the valve, a timing device, such as a repeating cycle timer oanbe connected to the power means of the electric motor to intermittently operate the said motor by providing for a shut-off of the motor when the valve is in the closed position. Thus, any leaks through the valve willbe detected during the shut-off period of the motor.

To synchronize motor shut-off with the closing of the valve, the said timing device can be electrically connected to the shiftable member 73,

thereby to operate when "member 73 is in a position corresponding to the closed position of the valve.

'The above described arrangement of a timing device is of a conventional nature, and itisnot It should be noted that the employment of a timing device, as described above, may require a lost motion connection between the shaft I3 and the valvestem connected thereto Thus, the momentum of the machineiand the driving motor after shaft reversal will be expanded in lost motion rather than transmitted to the valve after the latter has fully closed. Such a lost motion connection merely insures closing the valve under the predetermined torque as described above and prevents the machinery momentum from opening the valve after the motor is shut off by the timing device. This lost motion connection could consist of a; running threaded connection between the shaft I3 and the valve stem having the threads on an intermediate sleeve which is provided with a keyway to permit the axial movement of the'threaded connection.

provided an automatic shaft reverser and a torque limiter which operates off a constant driving force. Also, it should; be'apparent that the driving force may b e ;appliedto athe-Lmachine It should be understood that there "is-herein -Whilethe' driven shaft 29 prevented fIOmTIO- "tating and 'no damage will result. "The latter provision is a "desirable feature of the cam operation 'whichallows one section 3! 'of the shaft I3 to rotate while the other section 29 is stationary.

Although this invention has been described in one preferred form, it should not be so limited, as'it is susceptible to many changes withoutdeparting from the spirit of this application or thescope ofithe appended claims.

I claim: a I i "'1. A combination shaft reverser and torque governor machine, the combination comprising a separated shaft, :a drive gear for'the shaft,

two oppositely disposed driven gears loosely mounted on said shaft to-continuously mesh with the said drive gear, a double clutch member "mounted intermediate the said driven gears, a

sleeve mounted over the separated portion of the said'shaft, resilient means cooperating with the said sleeve and connected to the said shaft to normally maintain the same in rotative relation, a cam surface on the said sleeve, a cam follower attached to the said shaft to effect axial displacement of the said sleeve, a slidable actuator member connected to the said'clutch, a pluralityof springs mounted to separately act on the said actuator member to move the same, means actuated by rotation of the said shaft to load the said springs,- catch means to secure the said springs and be operable with predetermined rotation of the said shaft, and trigger means extending from the said sleeve to the said resilient means to release the catch means upon -means for receiving rotary driving power, a separated shaft, a double clutch member mounted to reciprocably slide on the said shaft, two oppositely disposed driven gears loosely mounted on the said shaft to mesh separately with the said clutch member, a joining member connected to the said shaft to cooperate with the separated portions thereof and to transmit rotatable mo- ,tion therebetween, cam means acting on the said joining member to further separate the said shaft sections when a predetermined resisting torque is applied to the said shaft, spring means acting on the said joining member for securing the said shaft sections in normal driving relation, a movable member attached to the said clutch member to operate the same, two springs mounted to act independently to position the said movable member, means actuated by rotation of the said shaft to compress the latter said springs, a catch mounted on the said movable member to secure the same in position against the compression of the said latter springs, means actuated by the said shaft rotation and means cooperating with the said camaction to alternately release-the said catch. I 3.- An automatic shaft reverser and torque limiter. machine comprising in combination, a separated shaft having a threaded portion at one end, two oppositely disposed gears loosely mounted on the said shaft, a driving gear in constant mesh with the said gears, double clutch means; intermediate the-said gears and splined *to the said shaft, a sleeve mounted over'said shaft separation, pin means on one sectionof saidshaft to maintain the "samein rotative relation with the said sleeve, a'cam surface on jthe said sleeve. pin-means eathe s'aidshaft 9 to cooperate with the said cam, spring means to yieldingly urge the said sleeve against the latter said pin means, a slidable actuator member attached to said clutch, a second spring mounted to abut ends of the said actuator, threaded 'means cooperating with the said shaft threads to reciprocate thereon and to compress the latter of said springs, a catch to secure the said actuator against displacement, trigger means cooperating with the said threaded means and said sleeve to alternately release the latter of said springs.

4. A shaft reverser and torque governor machine comprising in combination, 'a shaft having a threaded portion, oppositely disposed gears loosely mounted on the said shaft, double clutch means intermediate the saidgears, a drive gear in continuous mesh with the said gears, a second shaft axially aligned with the said first shaft, a sleeve attached to the said second shaft, a cam surface on the said sleeve, a pin on the said first shaft to abut the said cam, spring means to maintain the said sleeve in driving relation against the said pin, an actuator member attached to said clutch means and slidable therewith, two separately operable springs disposed to position said actuator, a threaded member mounted on the threaded section of the said first shaft to move axially thereon and having means to compress the said two springs upon predetermined rotation of said shaft, a catch to maintain the said springs in compressed relation, trigger means cooperating separately with the said sleeve and the said threaded member to release the said catch upon predetermined axial movement of the said sleeve and said threaded member.

5. A combination automatic torque limiter and shaft reverser device comprising in combination, a separated shaft having a threaded portion thereon, oppositely disposed gears loosely mounted on thesaid shaft, a driving gear in constant mesh with the said gears, a double clutch member splined to said shaft intermediate the said gears, a sleeve member having at least one longitudinal slot therein, a cam surface on one end of said sleeve, a pin in one section of said shaft abutting said cam surface, a second pin received within the said sleeve slot for securing the said sleeve to the other section of said shaft, resilient means for yieldingly retaining the said sleeve against the said first pin, a threaded sleeve mounted on said shaft threaded portion to reciprocate thereon, a slidable member attached to the said clutch member, other resilient means mounted to separately influence the position of the said slidable member, rod means abutting the said other resilient means and connected to the said threaded sleeve, a latch mounted toact against the said resilient means, trigger means cooperating independently with the said firstnamed sleeve member and said threaded sleeve to alternately release said latch.

6. The subject matter of claim 5, including a scale graduated to correspond with the number of shaft revolutions, indicator means cooperating with the said threaded sleeve and terminating on the said scale.

7. A combination automatic shaft reverser and torque governor mechanism comprising a sectional shaft having a threaded portion, a pair of oppositely disposed gears mounted on said shaft, a third gear in continuous mesh with the said first-named gears, a double-faced clutch member intermediate the said first-named gears and in driving relation to the said shaft, a joining sleeve mounted over the said shaft Itobe non -rotatably connected to one section thereof, a

cam surface on the said sleeve, springmeans for yieldingly maintaining said cam surface to abut the other section of said shaft, a threaded member mounted on the said shaft threaded portion to reciprocate thereon, a slidable actuator member attached to said clutch member, two springs disposed to separately affect the position of said actuator, a rod attached to said threaded member to compress latter said springs, catch means mounted on said actuator to secure'the same against spring action, a second rod attached to said threaded member to release the said catch means, and a third rod attached to said sleeve to selectively release the said catch means.

8. An automatic shaft reverser and torque governor machine comprising in combination, a

oppositely disposed gears loosely mounted on said shaft, a third gear in constant mesh with said two gears, a double clutch member intermediate the said two gears, a sleeve mounted over the shaft a to be non-rotatable with one section thereof, a 25 cam surface on said sleeve, means on the opposite section of said shaft to cooperate with said cam, spring means acting on said sleeve to yieldingly maintain said shaft sections together, a slidable actuator attached to said clutch member, a resilient means mounted to alternately displace said actuator axially, a threaded sleeve to reciprocate on said shaft threaded portion, a rod attached to said threaded sleeve to load the latter said resilient means upon inward movement of said threaded sleeve, a catch mounted on said actuator to secure the same against the force of latter said resilient means, trigger means alternately operative with said threaded sleeve and with the said shaft sleeve'to release said catch. 7

9. The subject matter of claim 4, including shaft stop means operable on said second'shaft whereby the machine is adjustably set in relation to the respective members operative with said first and second shafts.

10. The subject matter of claim 8, including locking means operative on said actuator to maintain the latter with said clutch member in a neutral position of gear engagement.

11. An automatic shaft reverser and torque limiter machine comprising in combination, a

separated shaft having a threaded portion at one end, two oppositely disposed gears loosely mounted on the said shaft, each gear having a bevel gear and an integral driven clutch member, a bevel driving gear in continuous mesh with the said bevel gears, a double dog clutch member intermediate the said driven clutch members and splined to the said shaft to alternately drive said shaft through said dog clutch member, a sleeve mounted over said shaft separation and having an axial groove therein, pin means on one section of said shaft to engage said sleeve groove and thereby maintain the shaft in rotative relation with the said sleeve, a cam surface on the said sleeve, cam follower means on the said shaft to cooperate with the said cam, spring means cooperating with said sleeve to yieldingly urge the latter against said cam follower means, a slidable actuator member attached to said clutch member, a spring mounted to abut each end of the said actuator, threaded means cooperating with the said shaft threads to reciprocate thereon with shaft rotation and thereby compress the latter said springs upon suitable reciprocable movement, a catch to secure the said actuator against dis- 12 aifiw -pwefil 52191 .919 93 $11 95! 9 a hafi !.1i2= WQ'17WQ8@:9 al mat l QFETQQQ d iwnv c utch msimbrfi, t d Over hfi 1. m Q9 99 mn-maiablg aim! o ab e mlati e 39.10% mm 9? said fli m urfaqe. n.. ais 1 @v !.m .n, Q41 We 86 m c i n. at ai ghaiia wn g s te w h m. 0 sprin m ans-acti sa d le vs to. Yiel m tain said ha t. fiQiQI S no t firslrlm ion undgr a nmflfit xminedr limi gsi t mu a s i able. clutfihv aefiu tqr attaszh d msaig ut mhen. at east twQ. s rin mquntagl. 10v @129: sitely abut said, qtuat r, llI-fifldfii 12cm m re: c procate 91:. a d shaft tbm d d. nmtt sm x01 atta h d t said. threa gd, sleavwe. to. cpmnness. s a ter sprin s; upon. nwa d max ems at said; threa ed. sl eve. a. @atsh mquntsld. n. said. actur; at r t se u the ame a ainst the efiqrts ofsaid;

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tiv wi h r sp ctiv movme tr f aid hreaded; sleeve and saidshaft Sleeve to release said catch: and th r by displace said clut h to change en:- gagement of. said driven clutch members tn re:

verse rotating oi. gaid shafp.

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